Clinical taste deficits are rare disorders in the general population that occur at a rate well below that of olfactory loss (see Core). The dearth of taste patients renders the study of taste disorders difficult and, consequently, their treatment problematic. Yet, there is one prominent exception to this generalization; over 90% of all head and neck cancer patients who receive radiation therapy (radiotherapy) experience substantial taste loss and alterations of food flavor perception. These changes are major contributors to decreased food intake, anorexia, and weight loss. They also contribute to a significant decrement in general quality of life and an increase in suffering. Neither the full impact of radiotherapy on taste perception, nor the exact bases for gustatory abnormalities associated with it, is known. Radiotherapy may chronically alter the gustatory epithelia via repeated inflammatory insult, subsequent fibrotic and anti-vascular sequellae, and/or by genetic alteration of the epithelial/gustatory regenerative cellular processes. The long-term goals of this muttidisciplinary research program are: (1) to carefully document the magnitude, quality, and course of taste perception changes resulting from radiotherapy; (2) to simultaneously document morphological, histological, and molecular changes in the gustatory system that follow radiotherapy and relate these to observed perceptual changes; (3) to determine whether long-term gustatory deficits and abnormalities are caused by repeated, accumulated inflammatory insult, radiation-induced genetic alteration of reconstructive cells and stem cells, and/or the epithelial sequellae of these events, in order to begin to understand the causes of these abnormalities. This understanding will yield insight into potential therapeutic interventions for patients. It is also anticipated that the results will consummate in the development of patient outcome profiles providing important prognostic information to patients and their physicians and, ultimately, improve patient care and quality of life. Finally, information about how insult from radiation treatment compromises taste function may provide new insights into fundamental processes underlying normal orosensory biology.